Throughout Season 2, their marriage remains legally intact, despite Fitz’s deep emotional and physical affair with Olivia Pope. The closest the show comes to this topic is in ("Molly, You in Danger, Girl"), when Fitz finally asks Mellie for a divorce. Mellie flatly refuses, explaining that divorce would destroy his chances at re-election and her own political future. She famously tells him that they are stuck with each other.
In the context of Scandal (Season 2), Fitz and Mellie do get divorced. does fitz divorce mellie season 2